Concrete roadways are normally made from concrete sections, each section being separated from its next adjacent section by an expansion slot. These expansion slots are utilized to enable thermal expansion and contraction of the roadway at the slot. This precludes cracking of the concrete when subjected to stress and strain created by fluctuations in thermal conditions.
In certain roadway surfaces these expansion slots can simply be filled with appropriate materials which will resile during thermal expansion and contraction and which will constitute a smooth transition from one concrete section to another by vehicular traffic. However, for concrete to concrete interfaces in other applications such as parking decks, ramps, stadiums, bridges, pedestrian walkways or the like other more complex systems must be utilized in an effort to effectively and durably fill and seal such slots while still accommodating the expansion and contraction of the concrete.
Numerous configurations of preformed rubber, elastomeric or metal members or combinations thereof have been manufactured to various shapes and designs for use in filling in the space between concrete slabs. The principal difficulty with all such prior art structures is that they lack durability over time and can, after a short period of time, cease to provide the effective joint which permits adjacent concrete slabs to expand and contract under varying conditions of temperature to preclude cracking of the concrete. Deterioriation and failure of the joint structure can also result in a space between the concrete slabs rendering a discontinuity between adjacent concrete slabs. This would result in the inconvenience and discomfort of vehicular traffic thereover. Further, all such prior art expansion joint systems are relatively costly and require excessively time consuming installation procedures.
Among the prior art devices used as expansion joint systems are those described in U.S. Pat. No. 4,279,533 to Peterson et al and U.S. Pat. No. 3,722,379 to Koester. In each of those systems, however, the performance is inferior as compared with the system of the present invention. Also, the costs of materials and installation time in prior art devices are relatively high as compared with the system of the present invention. In summary, the system of the present invention increases life, durability and performance while decreasing costs as compared with all other known expansion joint systems.